This was Pakistan’s first first-class match on English soil since their controversial “spot-fixing” tour of 2010.
During that year’s Test against England at Lord’s, Amir and Pakistan new-ball partner Mohammad Asif bowled no-balls to order on the instructions of their captain Salman Butt as part of a sting operation carried out by a tabloid newspaper.
All three received five-year bans from cricket and, together with sports agent Mazhar Majeed, jail terms.
However, Amir returned to international cricket earlier this year and could make his Test comeback at Lord’s, where Pakistan face England in the first of a four-Test series on July 14.
Although selected for the Somerset match, his return to action in England was delayed when Pakistan captain Misbah-ul-Haq won the toss and batted.
Misbah was out for a duck but several other members of Pakistan’s likely Test match top-order spent time in the middle at a sun-drenched Taunton.
After the captain was dismissed, Younis and Asad Shafiq (80) shared a fifth-wicket stand of 179.
Pakistan opener Mohammad Hafeez hooked Somerset and Scotland paceman Josh Davey over fine leg and pulled him over mid-wicket for two sixes in as many balls.
He was then reprieved by Davey on 17 when the bowler dropped a return catch.
But Dutch bowler Paul van Meekeren, who only joined Somerset last week, made the breakthrough when he bowled Hafeez for 20.
Pakistan were 79 for one at lunch but lost three wickets in the second session against Somerset’s multi-national attack.
Azhar Ali (20) was well caught by diving wicket-keeper Alex Barrow off van Meekeren.
Left-handed opener Shan Masood, strong off his pads, was dropped by Davey on 17 when the bowler failed to hold a return catch and missed down the legside on 39 when Barrow couldn’t cling on to a tough chance.
But in between the reprieves he batted attractively until, on 62, he was lbw to seamer Tim Groenewald.
Two balls later Groenewald, born in the same South African town as former England batsman Kevin Pietersen, had Misbah out for a duck with the aid of a fine slip catch by Tim Rouse.
The luckless Davey went wicketless after former England batsman Marcus Trescothick dropped a tough slip catch when Younis was on 20.
Younis went to fifty when he swept off-spinner Dom Bess, making his first-class debut, for a seventh four in 105 balls.
Shafiq also went to the landmark with his seventh four, but in 69 balls, when he late-cut left-arm spinner Jack Leach.
There was more bad luck for Davey when Younis’s inside edge on 75 evaded the diving Barrow.
Shafiq’s 120-ball innings ended when he was well caught by Bess at point off Leach.
It seemed Younis would get to his 53rd first-class century before stumps, with some elegant late cuts taking him well into the 90s.
But instead he was left one run shy of a hundred, with Sarfraz Ahmed (six not out) unable to get off strike.
This fixture is Pakistan’s first of two three-day games before the first Test at Lord’s, with the Pakistanis also playing Sussex at Hove from July 8-10.